A survey of the transmitter synthesizing enzymes, choline acytltransferase, glutamate decarboxylase, and tyrosine hydroxylase, is to be completed in the organ of Corti, auditory nerve, spiral ganglion, cochlear nucleus and inferior colliculus as a first step in identifying these transmitters. Based on the outcome of these studies, additional experiments will be designed to determine neurotransmitters active in the cochlea and cochlear nucleus.